Q.Which of the following compounds will be formed when aniline reacts with H2SO5?

Oxidation of Amines

Amines, especially aromatic ones, are easily oxidised because the nitrogen lone pair and, in anilines, the electron-rich ring are both vulnerable to oxidising agents. The products depend on the oxidant and conditions, and aniline in particular gives a whole range of nitrogen oxidation states.

For aniline ($C_6H_5NH_2$):

• With Caro's acid ($H_2SO_5$, peroxymonosulphuric acid) or other peroxides, controlled oxidation gives nitrosobenzene ($C_6H_5NO$), then nitrobenzene ($C_6H_5NO_2$), passing through phenylhydroxylamine ($C_6H_5NHOH$).

• With strong oxidants such as acidified $K_2Cr_2O_7$, aniline is oxidised to the black-brown dye aniline black, and under milder chromic acid conditions to p-benzoquinone.
• Mild oxidation/coupling can give azobenzene ($C_6H_5-N=N-C_6H_5$), an azo product. …